Among the familiar faces on stage was longtime Metallica bassist Jason Newsted, who joined the band for a rendition of "Harvester of Sorrow" from ...And Justice for All.

And speaking of the past, some of Metallica's influences were also on hand as well, including Saxon's Biff Byford, who joined the band for "Motorcycle Man" as well as Sean Harris and Brian Tatler of Diamond Head. The pair played four total tracks with Metallica: "The Prince, " "Helpless," "It's Electric" and "Am I Evil?"

Finland's Apocalyptica added some furious cello playing to "One" and "No Leaf Clover," a track rarely played since S&M.

Also on hand was Metal Church's John Marshall -- a former Metallica guitar tech who filled in for James after his unfortunate run in with some pyro in August of 1992 -- who joined Metallica for "Sad But True."

While Metallica are keeping things quiet about future guests for their 30th anniversary celebration, Ozzy Osbourne and Lemmy Kilmister are two names being floated around as likely to appear.